Rather than using a percentage I would again recommend you talk to a property manager or local investors and ask them what they budget for annual per unit expenses.  

This is probably not what you want to hear but if you have not been able to afford even the minimum on your student loan payments you are not in a financial situation to buy real estate.It may be more useful to either increase your income, create a monthly budget that allows u to pay all of your bills and increase your savings, and/or sell any cars with loan payments and buy a beater car.

Finally, I found a property that was in my budget and located in a good neighborhood.

Projecting $30k annual net operating profits (after paying monthly mortgage & service costs.)Cash invested $90k (closing costs, repairs/improvements & adding furniture, TVs, appliances, etc.)Cash borrowed: $463kHours invested: 500Projected annual revenue $70kAnnual mortgage, taxes, insurance $37kAnnual maintenance & cleaning $20kAnnual repair budget $10k Lessons learned?

It helps to establish a timeline and budget: A scope of work should include a timeline for completing the various tasks and milestones, as well as a budget for the project.

Get rid of debt, build a budget, and save.

-Purchase price is asking price from the seller, closing costs are estimated at 4%-Conservative estimate for ARV ($210k), Comps are closer to 250k+-Repair costs budget set at $20k, home only needs submeters and cosmetic work (have not inspected the property yet)-down payment set at 25% incase the bank requires it, however, 20% preferred.

Went over budget on the reno.

Can you downsize your car or phone or entertainment budget?

(That being said, it's easy to go over budget on a rehab or overestimate the ARV, so be very careful with this.)Overleveraging overall is having too much debt to cover your expenses or not enough liquid cash.